Loading your revision module…
Marine Radio revision module 8 of 10
MMSI, Channel 70, routine individual calls, distress alerts, acknowledgements, and DSC follow-up voice procedure.
9 guided lessons · 19 practice questions · 19 flashcards
Use this module hub to choose the right lesson, then open the dedicated lesson page for the complete explanation, worked examples, FAQs, and practice questions.
A VHF DSC set transmits digital signalling on Channel 70. Depending on the call, that digital packet can identify the caller and addressee, state a priority, propose a working channel and...
Read the full lesson: What DSC DoesAn MMSI is transmitted over the radio path to identify a maritime station or group call. Ofcom assigns the relevant identity through a Ship Radio or Ship Portable Radio Licence. A ship-st...
Read the full lesson: MMSICall type answers who should be alerted: for example an individual station, a defined group or all ships. Priority or category answers why: routine, safety, urgency or distress. The avail...
A correctly configured DSC radio can ring a selected station or relevant receivers and attach a station identity to the call. A distress alert may also include nature-of-distress selectio...
Read the full lesson: What DSC AddsWhen a VHF DSC distress alert sounds, immediately cease any transmission that may interfere with distress traffic and continue a listening watch on Channel 16. Read the received message w...
Read the full lesson: Distress Alert Reception And AcknowledgementITU Resolution 349 (Rev.WRC-23) gives the VHF DSC cancellation sequence. Reset the equipment immediately. If the set supports cancellation, cancel the alert using the equipment procedure....
Read the full lesson: False DSC Distress AlertFor a known vessel, select or enter its verified MMSI, choose an individual call with routine priority and indicate a suitable inter-ship radiotelephony channel. Send the call and wait. W...
Read the full lesson: Routine Individual DSC CallsA ship-station MMSI has the form MID plus six digits. The three Maritime Identification Digits identify the administration having jurisdiction over that ship station. A coast-station iden...
Read the full lesson: MMSI Structures And DSC Call TypesBefore relying on DSC, check the programmed MMSI against the station licence, inspect the displayed position and UTC and confirm that automatic data is current and plausible. If the navig...
Read the full lesson: Position, Received Messages, Tests, And False AlertsAdd the complete practice layer
Keep reading the public lesson articles, and add this module's guided flow, quizzes, spaced-repetition flashcards, progress, and mock exams with one payment.